(a) Modern improvements in management of patterning and grain—The Garcia invention mentioned above, together with previous related work, has brought to inkjet printing a remarkable, unprecedented degree of systematization and orderliness in the control of printmasking for suppression and balance of both patterning and random granularity. Those developments have created an opportunity for ready expansion of inkjet printing into many new applications that entail printing on a great variety of special-purpose printing media.
(b) The challenge of specialized print media—Such special purposes and their associated printing media may range from metal-foil-like materials, through bulk-matte synthetic papers, to extraordinarily porous fabrics or membranes. They are in fact so great in number that it is impractical for major manufacturers of inkjet printers—particularly large, printer/plotter-scale units suited for industrial use—to give adequate attention to the unique inking requirements of such diverse industrial materials.
Unfortunately for the resolution of this problem, conventional printing systems have factory-established fixed relationships between the data manipulations necessary to image rendition and the calorimetric tone hierarchies produced by actual ink on actual printing media. Such fixed relationships are essentially taken for granted in the industry.
Rendition calculations—particularly but not exclusively dither masking for commercial graphics, and error diffusion for photo-like and other continuous-tone images —are very well known in this field and extensively disclosed and discussed in dozens if not hundreds of patents on this subject. The later processing stage of printmasking is also very well elaborated in the patent and other literature, perhaps culminating in the Garcia innovations.
(c) Early partial responses to the challenge, and their limitations—Inkjet printers exhibit various approaches to accommodating diverse inking requirements. Common to substantially all these, however, is internal control, by the printer manufacturing company, over the above-mentioned relationships between rendition processing (and printmasking) and the tone hierarchies in the low-level output printing stage.
On one hand such control is extremely beneficial, because these relationships—while in most cases deceptively appearing simple and straightforward—are often inordinately demanding of attention from ink chemists, color scientists, and advanced programmers. The printer manufacturer's personnel may be best equipped to deal on a large scale with such problems.
On the other hand, many special printing materials are employed in relatively very specialized industries that cannot support more than a few large-format printers. Such industries may be popularly described as “niche” operations in that they cater to manufacturing or other industrial activities which are important in their own environments but virtually fit into mere small recesses in the overall industrial woodwork.
In such circumstances it becomes uneconomic for key personnel of an extremely large manufacturer to attend to such special needs on an individual basis. This problem is exacerbated by the relative ungainliness and large overhead associated with activities of a printer manufacturing firm.
(d) Advent of the nimble RIP—In recent years, the special needs and challenges of some of these niche applications have been undertaken, and very advantageously so, by companies that do not manufacture printers, or computers either—but rather manufacture a new kind of device known as a raster image processor. Such a special-purpose processor has most commonly taken the form of a physically separate, and separately manufactured and marketed, electronics module that takes on image-manipulating chores previously performed in the computer or printer, or both.
In many cases the processor justifies its existence simply by relieving the general-purpose computer of time-consuming massive computations, freeing that more versatile computer for a variety of other tasks more demanding of its general abilities. In other applications, however, the processor serves a higher purpose:
A relatively smaller company that manufactures raster image processors, by virtue of the greater economic and operational agility that goes with lesser size, is much better suited to address the science and engineering requirements of printing in a niche industry. Thus the processor company can be nimble enough to serve a need and make an attractive profit from operations that would be impractical for a printer company.
(e) Remaining limitations—Yet a partial obstacle to this solution remains. Conventionally, as mentioned above, the printer company—and the printer itself—provide to the outside world only a fixed relationship between rendition math and output tonal hierarchies.
This means that a processor company, having once determined that a special relationship is needed, must still beseech the printer company for installation of a custom ROM, or PROM, or in some cases an even more thoroughly buried functionality, that defines the rendition/output mapping. The last-mentioned situation may be typified by a need to circumvent a fixed operation built into an application-specific integrated circuit (“ASIC”) that is a sort of hypothalamus in the printer.
Although in most situations an identifiable module containing the necessary mapping function is actually present in the printer, yet the problem remains because that module is relatively inaccessible to the processor company. Furthermore its syntax may be incompletely plain to even skilled programming personnel of the processor company.
(f) Known distributive tonal-hierarchy schemes—Nevertheless the raster image processor (“RIP”) has earned a rightly established place in the inkjet printer industry, so much so that a current generation of some printer products includes a RIP that is essentially built in. This type of arrangement represents one new kind of partnering among business entities: in this case, for purposes of this document, the RIP manufacturer in practical effect (though not in legal effect) becomes a part of the printer company.
Here the RIP is very loosely an “internal RIP”. The two companies are termed “affiliated”.
Where a processor is instead sold separately, for purposes of this document the processor is called either simply a “processor” or an “external RIP”—and in practical effect the processor manufacturer does not become part of the printer company, and the two are termed “unaffiliated”. The processor may most typically be installed by the end-user, or alternatively by a representative of the processor company; merely for purposes of this document, such an arrangement is not termed “partnering”.
Both these kinds of distributive arrangements for managing tonal hierarchy have been classically known, at least in diverse industries, as “OEM” or “original-equipment manufacturer” situations. In some industries, only one or the other would be regarded as truly OEM.
(g) Conclusion—This discussion has focused upon limitations in the ability of both a printer company and a processor company—either one acting alone—to fully deal with needs of specialized printing applications. These limitations continue to impede achievement of uniformly excellent inkjet printing in greatly diverse industries. Thus important aspects of the technology used in the field of the invention are amenable to useful and important refinement.